What is an EoU Chart? A Complete Guide to Evidence of Use in Patent Law

An EoU (Evidence of Use) chart is basically an analytical document that systematically illustrates how claim(s) of a particular patent are being practiced by an infringing product. An EoU chart breaks down each and every element of the claim(s) and clearly shows how those elements are identified in the infringing product. The EoU chart is also called a Patent-to-product mapping or claim-to-product mapping or claim chart.

In other words, the EoU chart includes a mapping of claim elements to the product and is used to ascertain the extent that the product reads on to the claim. A thorough search is performed on the identified companies and their product portfolios are analyzed in order to find the best infringing product. Further, Granular mapping of the target claim elements is performed to clearly indicate the presence of each element in the products/standards.

Importance:

EoU charts plays a vital role in patent litigation as they provide strong evidences that support the patent holder's assertion of infringement.

Further, EoU charts are also used to show the patent value in terms of its usage in the current market products/technology. EoU charts can also be useful for the patent holding entities for seeking licensing opportunities.

Consequences of not preparing EoU charts

• The patent holding entity might be unable to clearly show the infringement of its patents by unauthorised use by others.
• If the patent holder goes for litigation for its patent infringement, not preparing well-reasoned EoU charts can weaken its case in the court.
• For licensing opportunities, patent holding entity might not be able to convince the other party for licensing without strong EoU charts for its patent portfolio.
• The patent holding entity might not be able to stop others from unauthorized use of its invention, which can dilute exclusivity of its patents.

Foundations of EoU Chart

EoU chart is a practical tool that directly supports and implements several fundamental legal requirements for proving patent infringement.

Patent: The fundamental principle underlying an EoU chart is a patent. Basically, a patent is a right to exclude others from making, using, or selling a claimed invention within the territory where the patent is granted, for a particular period of time typically 20 years.

How Patent Claims are mapped in EoU chart: The scope of a patent's legal protection is defined by its claims. When an EoU chart is prepared, the claims, generally independent claims are mapped to show that all the elements of a claim are present in the target product. EoU charts can also include dependent claims mapping along with independent claims depending on the client’s requirement. EoU chart typically takes the form of a table with several rows and columns.

Fulfilling criteria: In EoU charts, while mapping a patent with an accused product, the product must meet the date criteria and the product should currently operate in the market. The accused product’s release or launch date must be later than (or at least on) the earliest priority date of the patent claim.

Importance of EoU Chart

• In Patent Litigation: EoU charts plays an important role in patent litigation cases as they provide strong evidences that support the patent holder's assertion of infringement.
• Clear Demonstration: EoU charts help to demonstrate how the infringing product falls within the scope of the patent claims.
• Showcase Patent Value: EoU charts are also used to show the patent value in terms of its usage in the current market products/technology.
• In Licensing Opportunities: EoU charts can also be useful for the patent holding entities for seeking licensing opportunities.
• In lawsuits: A well-reasoned and strong EoU chart can influence the outcomes of the infringement lawsuits.
• Strong Charting: EoU chart with specification support can further strengthen the claim mapping against the accused product.

How to Prepare EoU Charts?

Following steps are performed in the preparation of the EoU charts:

• Understand the Patent: The first step is to perform a thorough understanding of the subject patent and review of the patent's claims, specification, file wrapper, etc. Then, the broadest independent claim, the key elements and limitations described in the claims are identified.
• Identify Potential Infringers: Potential infringers are identified and their products or technologies are analysed that may infringe on the patent.
• Analyze the Accused Product or technology: The accused product or technology is examined in detail to identify its features, components, or steps. This involves a thorough search including going through the product detailed documentation, product teardowns, etc.
• Compare the Accused Product/technology to the Patent Claims: The claim elements are compared with the features of the accused product or technology and determining whether each element in the claim is present or not in the accused product/technology.
• Mapping: The target claim elements are mapped using colour coding to clearly indicate the presence of each element in the infringing product/technology.
• Format: EoU charts are prepared either in the word document or PPT depending on the client requirements and/or instructions.
• Guidelines: Generally, claim(s) elements are put in the left side column of the table and product evidences are put on the right side column of the table. Each claim element is mapped in a separate row-by-row manner.
• Commentary: Analyst comments are added on each and every slide/page to tell the story line and walking through the claim chart.
• Strengthening the chart: Apart from that, specification support can be put along with the respective claim elements to further strengthen the mapping.
• Claims: Generally, independent claim(s) are put in the EoU chart. However, dependent claims can also be mapped depending on the client requirements.
• Continuous Updates: Patent litigation may present new evidence at any time. Therefore, the prepared claim charts should be regularly updated with any new evidence or updates to accurately reflect the current information. The flexible nature of the charts allows for the most current information to be included throughout the litigation process. A well-constructed claim chart in patent litigation supports arguments and enables a more streamlined litigation process through clearly presenting and supporting uses or lack of infringement with direct evidence.

Sample EoU chart snapshots

 

Tools & Resources in EoU Chart preparation

• Evidences Gathering: For EoU Chart preparation, first the infringing product and its related evidences are identified from the documentation available online, from company’s websites, forums, and videos etc.
• Tool for Standards: For standards based products, Effectual Services use special tools to gain insights in the standard related documentation.
• Source code review/Product testing: In some cases, if required the product source codes is checked, reverse engineering or product teardowns is performed, to gather evidences for the corresponding claim elements which are hard to find in publicly available documentation.
• Reporting Tools: After gathering evidences for each and every claim element, the EoU chart is prepared, using software tools like MS Word, PowerPoint, Excel, etc. depending on client requirements and/or instructions.
• Using Trusted/Official sources: Preferably, the evidences from the infringing product’s official website and other official resources are considered. Sometimes, third party sources are also used to support and strengthen the mapping, if required. For standard based products, the latest standard documentation from the standard providing entities like ITU-T, 3GPP, IEEE, etc. is used.
• Standard Format: The EoU charts are prepared in a standard format, keeping fonts, colors, sizes, snapshots, links, textual data, etc, in a systematic manner, for a clear understanding and readability of the EoU chart.

Handling EoU Charts

After preparing EoU charts on the potential infringement cases, there are few steps that can be followed:

• Discussion of the EoU charts with the client and other authorities involved in the project for further escalation.
• One of the important steps that can be taken is ensuring that the infringed patent is valid and enforceable, by conducting a validity search of the infringed patent.
• Further, the patent holder can use the EoU charts and go to the infringing party for seeking the damages.
• The patent holder can also use the EoU charts to utilise them for licensing and monetization purposes, EoU chart showing the value of patents.
• The patent holder can also file a case in the court against the infringing party and utilise the EoU Charts in the litigation process to show the intent of infringement.
• We, at Effectual Services have experts and professional legal teams that can provide consultation at every step involved in the process, be it litigation or licensing strategies or any other legal consultation requirement.

Legal Significance

An EoU chart is a legal document that maps the claims of a patent to specific features of a product, and demonstrates how the patented invention is used, intentionally or unintentionally, by the infringing product.

EoU chart holds an important legal significance and can be used in various scenarios:

In Patent Infringement: EoU chart plays an essential role when it comes to demonstrating infringement by showing that a product has all the claim elements of a patent.

In Licensing and Monetization: EoU charts are a valuable resource for licensing and monetization businesses. As it helps the patent holding entity to show the value of a patent based on its practical application in the current market products.

In Patent Litigation: EoU charts are used to present evidence of infringement in court, to help the court understand the relationship between the patent and the accused product.

In Pre-Litigation Research: EoU charts are also used to assess the strength of a patent and identify potential infringers in the market before litigation.

Industry/Technology Specific Considerations

For every industry, while the basic fundamental structure of an EoU chart is more or less the same i.e. claim element vs the accused product, the preparation and evidences gathering of an EoU chart are significantly influenced by the specific industry/technology involved.

Software related: Software related EoU charts preparation require evidence gathering from source code review, API documentation, user interface analysis, screenshots, video recordings of software in use. It requires understanding how software components interact and identifying potential patent infringements that may be hidden within lines of code.

There are certain tools that can be used to help source code experts to analyze the code namely WinGrep/PowerGREP, Microsoft Visual Studio, Notepad ++ etc.

Standards related: There are certain cases where the patents are related to specific standards like telecom patents, Wi-Fi patents, video compression, etc. For preparation of EoU charts in such cases, the standard related documentation has to be analysed from their official providers like ITU-T, 3GPP, IEEE, etc. Further, Effectual Services has an in-house tool used for performing standards related infringement searches and gathering evidences for chart preparation. In the claim chart mapping, the latest versions of the particular standards are used.

Semiconductor/Fabrication related: For semiconductor or fabrication cases, there is a different approach that is followed while gathering the evidences for chart preparation. In such cases, the target products might have very limited evidences to show infringement as fabrication level details are merely disclosed by the companies. For these types of cases, the standard or commonly used fabrication details can be used from third party sources for trivial elements. For main/novel elements, apart from the available product documentation, the research papers or educational documentation of the target product/company is considered to gather the required evidences.

Cases requiring reverse engineering/teardowns: There are some case in which the reverse engineering or teardown of the target product is required to gather the required evidences for chart preparation. For such cases, Effectual Services has a team of experts that are specialized in reverse engineering of products/technologies. Further, sometimes it is required to work with the client for reverse engineering or teardown related cases and prepared strong EoU charts for such cases.

Real-World Case Studies

Case 1: One of our clients once approached us for an EoU chart generation project for some of their patents against a given set of companies. The aim of the project was to identify potential infringers and go for licensing opportunities for their portfolio. In our initial analysis, we performed product search on the given set of companies and identified some high potential infringing cases against the products of the given set of companies. After discussing the high potential infringement cases with the client, we proceeded with the EoU chart generation. We prepared some strong EoU charts for the identified cases and provided the same to the client. The client used our charts in the licensing strategies and was very impressed with our outcome. We were appreciated by the client over the call.

Case 2: Once a new client, who is a big market player, approached us for an EoU chart generation project for a set of patents, it was an open search project. The objective of the client was to identify potential infringers and go for infringement lawsuits against them. The client wanted us to target only larger manufacturers or big players so that he can seek good amount of damages from them. We identified some large manufactures related to the patent portfolio domains and performed product search in these large manufacturers. As a result of our findings, we were able to identify some high potential infringing products from these manufacturers. After a thorough discussion with the client over these cases, we finally prepared the EoU charts for the identified cases and shared them with the client. The client used our EoU charts for filing the infringement cases against the infringing companies. The client highly appreciated our efforts and results.

Common Misconceptions

• ‘An EoU chart is merely a comparison table’: While EoU charts are generally presented in a table format, it does not mean EoU charts are simple tabular data. They represent a deep legal and technical analysis. Each row holds a major significance, mapping each claim element to complex technical features, supported by their respective evidences. EoU charts are strategic documents.
• ‘An EoU chart guarantees a win in court’: One of the major misconceptions regarding EoU charts is that if you have an EoU chart, it means you will surely win the infringement lawsuit. Basically, an EoU chart is a tool to prove infringement in the court, not a guarantee of victory. It is used for showing potential infringement, however, there are various other factors (e.g., validity of patent) considered in a patent dispute.
• ‘EoU charts are only for litigation’: A common myth is that EoU charts are only used for litigation purpose, however, EoU charts are an invaluable source for licensing negotiations, patent monetization, Strategic IP management, understanding the commercial relevance and value of patents within a portfolio, etc.
• ‘AI can fully automate EoU chart generation’: With the growth of AI in IP field, there are certain tools in the market claiming AI-based chart generation, however, AI can assist in EoU chart preparation e.g., by quickly identifying relevant documents, suggesting mappings etc., it cannot fully replace human oversight when it comes to legal judgment, the implications of prosecution history, confidentiality, etc.

Way Forward

An Evidence of Use (EoU) chart is a vital tool for demonstrating how a patented invention is practiced by a product or technology in the market. By systematically mapping patent claim elements to features of an accused product, it provides clear technical and legal support for identifying potential infringement.

Beyond litigation, EoU charts help patent holders showcase the real-world value of their patents, support licensing negotiations, and guide strategic IP decisions. When prepared with strong evidence and proper analysis, EoU charts become powerful documents that strengthen infringement claims and enhance the overall value and enforceability of a patent portfolio.

How can Effectual help – Our expertise domain wise in EoU Charts generation

• At Effectual, we have a huge team of experienced workforce. The team consists of Engineers, Bachelors, Masters and PhDs from various technical backgrounds, including Computer Science and Information Technology, Electronics and Communications, Electrical, etc. Hence, we have expertise in a variety of technical domains for EoU Chart generation.
• Our techno-legal professionals are quite experienced when it comes to correlating the marketing language of the products with technical terminologies, to relate the product feature/functionality with the patent claim elements and efficiently show the claim elements mapping to the infringing product evidences.
• Many of our team members have Law degrees along with the technical degrees which make our team members an ideal fit for Intellectual Property related services. We can provide consultation at each and every step involved in the process of EoU charts generation and further legal proceeding with EoU charts.
• We have experienced team members in different domains like software domain, semiconductor fabrication domain, standards related domain, telecom or Wi-Fi domain, machine learning domain, etc. for creating EoU charts.

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